Pipe protractor



Nov. 16, 1943. c. H. LEHNUS PIPE PROTRACTOR Filed Feb. 4, 1943 Qwumwo b NUS F ii R (I x A a C a This inventionrelates to-pipeprotractors, and

has for one ofv its objects the production of a simple and efiicientmeans for facilitating thecaccurate marking of angles on pipes and other round objects. E A further object of thisinvention i's the production of a simple and efiicientp'ipe protractor which is provided with an adjustable'pipe-encircling element for snugly fitting around a pipe while the element is extended atan angle to the 'transverse'axis of the pipe to facilitate theaccuratemarking of an anglecut tobe made upon the-pipe. Other objects invention will appear throughout the following specification andclaiims: l

Inth'edrawingz I Figure-1 is a top plan view of the protractor mounted upon a pipe;

Figure 2 is a side elevational view of the protractor;

Figure 3 is a front elevational view of the protractor;

Figure 4 is a fragmentary longitudinal sectional view taken on line 44 of Figure 3 l By referring to the drawing, it will beseen that l designates the pipe which is to be cut at an angle to the transverse and longitudinal axis thereof on the angle line A-A indicated in dotted lines in Figure l. A supporting yoke II is provided which consists of a longitudinally extending angle member, and which yoke is adapted to fit upon the topface of the pipe and extend longitudinally thereof. An anchoring clip I2 is secured to the top face of the yoke l l, as shown in Figure l, and this clip l2 carries at one end a bolt l3, which bolt I3 is connected to one end of an anchoring chain M, which anchoring chain I4 is adapted to pass around the pipe In as shown in Figures 1 and 2. The opposite end of the clip I2 is provided with upwardly extending fingers 15, between which fingersfis adapted to be fitted the free end of the anchoring chain M to adand'advantages of the present justably hold the chain around the pipe H), as

shown in Figure l. i

A protractor plate I6 is pivotallyrsecured, as at IT, to one end of the supporting yoke I l, and this protractor platelfi is graduated, as at I8, with the degree of a circle near its periphery I9. A locking plate 20 is supported upon the sup orting yoke l I, as shown in Figures 1, 2 and 4, by means of a threaded bolt 2| which bolt 2| is carried by the supporting yoke II and a thumb nut of a suitable type 22 is carried by thebolt 2i and engages the locking plate 20 for firmly holding arms 29 arein the nature of links which straddle UNIT D :sTA Es PATENI OFF CE v, V ffrrcisrnomAo'ron, H I g i H Carl fll chnus,LyonsQKansQ I I V 2 l in Y, xisaitaitnmmay 4,1943, SerialNo. 47431371. :7 3

V (ores-755 J I the lockingplate in engagement with the pro-- tractor plate 16; as shown in Figure 4. Thelockq ing plate 20 is preferably provided with a downwardly turned forward end 23 which overhangs the protractor plate 16 near its periphery l9 to facilitate the locking of the protractor plate IS in a set selected'and adjusted position when the thumbnut 22 is tightened. A centralregistering mark is formed upon the top-'face of the locking plate 20, as shown in Figure 1, to facilitate the registration of the Scale 18 in a selected position with respect to the registering mark 24. The protractor plate I6 is provided with a downwardly turned fiange 25 at its'outer end, whichflange is adapted tof overhang the top of the pipe 10; and an adjustable pipe-encircling element in the nature of a pair of link jaws 26 is carried bythe flange 25; Each linkjaw 26' is piv*- otally secured, as at21,'to the flange 25, and each link jaw is formed of a plurality of pivotally connected links 28 which are pivotally secured to the pivoted connecting arms 29, which arms 29 are in turn pivotally connected to the pivots 21 carried by the flan e 25.

From the foregoing description it will be seen that the supporting yoke II is first placed upon the top of the pipe and the chain I4 ispassed around the pipe l0, and is secured in an adjusted position tothe clip I2, thereby holding the yoke ll firmly upon the pipe ID and longitudinally thereof. The angle nature of the yoke, which is substantially V-shaped, will cause the yoke to straddle the pipe I!) longitudinally thereof, and thereby resist shifting movement upon the pipe. The protractor plate H5 is then, set at the desired angle (by way of illustration note Figures 1 and 2), and the adjustable encircling element embodying the linkjaws 26 will be placed snuglyaround the pipe, in this manner definitely defining a non-yielding guide follownection in some other conventional manner.

It is important to note that the connecting the flange 25 andv that these links may be stretched outwardly to extend longitudinally of the flange 25 when desired, for the purpose of permitting the instrument to lie fiat for packing or the like. Also it should be notedthat the link jaws 26 may be adjusted to various sizes of pipes, depending upon the length of the'jaws 26. It should be noted that .it is highly 1mportant that some definite rigid guide is essential when marking angles upon a circular face, such as the contour of a pipe in order that a proper cut may be obtained to permit two pipes to be joined together at an angle particularly when welding. Consequently, by means of the linked jaws 25, Ihave provided such a means which is not only flexible but is at the same time sufficiently rigid tolpermit of an eficientmarking. g v Certain detail changes may be employed without departing from the spirit of the invention,

so long as such changes fall within the scope r .7 W15 Having described the invention, what l claiin of the appended claims.

1. Aprotractor of the class described numpris-ti ing a support adapted to extend longitudinally of and lie upon a pipe, flexible means 'for anchoring; the -support in position, a protractor plate ipivotally secured to-said support, -an-.ad-

. Justable encircling-element-suspended upon the protractor plate and adapted to snugly :flt against protractor plateland adapted to :snugly'fit against the contour of a' circular article-to bemarked, said encircling element comprising :a pair of pivoted jaws, each jaw comprising a plurality of links which links are adjustable relative to each other and the jaws being adjustable relative to each other, and a locking plate carried by the support and engaging the protractor plate for' locking the protractor plate at a set angle with respect to the support.

3. A protractor of the class described comprising a support adapted to extend longitudilnallyof and lie upon a pipe, flexible means for anchoring the support inigposition, a protractor plate pivotally secured to said support,'an adjustable encircling element suspended upon the protractor plate and adapted to snugly fit against -the =coritour of a circular article to be marked,

said;encir.oling element comprising a pair of pivoted jaws, each jaw comprising a plurality l of ilinks, whichfiinks are adjustable relative to,

eachmther and the jaws being adjustable relative to each other, a locking plate carried by the support and en'gaging' the protractor plate for locking the protractor plate atxra set :angle with respect to the supporuvand a'graduated ssca'le carried by the protractor plate-and adapted to register with the locking plate. 1

"4. A- pipe protractor of the classdescribe comprising :aL-support, a protractor .platepivotally securedlon said support and adapted to be adjusted at an angle to the longitudinal axis of said support, said protractor plate having 28. depending flange, and a flexible pipe-encircling element pivotally hung upon'said' flange adjustable to snugly fit the contour ofwa pipe, :said encircling element comprising a pairof oppositely arranged jaws, each-j aw comprising a plurality of links, the links of each, jawbeing adjustable relative to each other and the jaws being adjustable relative to each :other.

CARL LEI-INUS, 

